This invention relates to a geographic information system (GIS), or in particular to a management system for long objects, for example pipelines to transport liquids and gases such as oil and natural gas.
Conventionally, the geographic information system has been used for management of city water works and natural gas facilities. A display technique is available, for example, by adding the measurement data of the cathodic protection potential and the pressure to the image of pipelines (for example, JP-A-2003-185100).
According to this technique, the measurement points are predetermined by identification (ID) numbers and correspond to the ID numbers on a system chart. Thus, the data acquired with a specified ID number are displayed. Also, the time change data can be acquired and displayed by designating the measurement points.
A technique to visually grasp the historical change of tunnels is also available (For example, JP-A-2004-37419). In this technique, a measurement point, with the corresponding data obtained based on the distance from the measurement point, are displayed on the map. Like in the first technique described above, each measurement point is designated by a number, and the coordinates of the measurement points acquired in advance have corresponding measurement point numbers. In accordance with the coordinates from the measurement points and the designated time, the information on such as a crack corresponding to the designated time can be displayed.